Informational Guide

Does a Dehumidifier Help With Allergies?

If you are an allergy sufferer then you will need relief. Do dehumidifiers help with allergies? Learn how they can be of assistance inside the home.

by Josh M

Allergies can be such a pain, and the indoor environment in your home is often causing them. Pollen, pet hair, even dust mites in water droplets can all trigger allergies – but thankfully a dehumidifier can help.

Dehumidifiers primarily work to control humidity, but by influencing your home’s humidity they can have some other positive impacts on allergens. In this guide I’ll explain what’s causing your allergies, how dehumidifiers can reduce allergy symptoms, and how you should set up your dehumidifier for the best results.

Most Common Indoor Allergies

Seasonal Allergies

Seasonal allergies are allergies that occur during particular seasons, such as in the spring or the fall. Most seasonal allergies are caused by pollens (there are several types) in the indoor air. [1]

These pollen particles tend to cause “seasonal allergic rhinitis,” which is essentially an irritated nose. Your nose may feel itchy, runny, or stuffy because of the air pollution from this pollen. Pollen enters the home through air conditioner units, open windows, and simply opening doors to get in and out of your home.

Woman Sneezing Due to Allergy

Pet Allergies

Pets can cause and exasperate allergies. Both cats and dogs have allergens that are often associated with eye and nose symptoms in their owners. If you have red eyes, leaking eyes, a running nose, or a stuffy nose, then you may have a reaction to your pet’s dander [2]. This type of allergy is most common among people who suffer from asthma.

Humidity & Dust Mite Allergies

When the relative humidity is high then the excess moisture can lead to dust mites. The relative humidity is not responsible for allergies, but the higher concentration of dust mites can impact the air quality and trigger an allergic reaction.

Most Common Allergy Symptoms

If you’ve regularly got any of these symptoms then it’s likely you are having an allergic reaction, and it’s time to take action:

  • Stuffy Nose
    A stuffy nose tends to be associated with excess sinus pressure and a tight, congested feeling in the nose. Seasonal allergies are often the cause of a stuffy nose.
  • Dry Cough/ Wheezing
    The dry cough and wheezing symptom is another common allergy symptom. This one tends to be associated with hay fever, pollen, or mold. This can also be associated with pet dander allergies.
  • Bloodshot Eyes/ Watery Eyes
    Experiencing bloodshot eyes and watery eyes means that a type of allergen has penetrated the mucous membrane around the eye. This typically means that particles are getting into the eye. This happens a lot with pets who get near their owner’s faces. If you have a pet allergy, try keeping your pet at your shoulders or below the shoulders whenever possible.
  • Sore Throat/ Itchy Throat
    The sore throat or itchy throat often indicates that allergy sufferers need to drink more water, but it also indicates an allergic reaction to seasonal allergies. This tends to happen with pollen, hayfever, and other outdoor allergens that make their way indoors.
  • Breathing Difficulty/Chest Tightness
    If you have breathing difficulty or notice that your chest feels tight, you may be suffering from allergies. This is a common symptom for people with asthma to experience when allergens are present.
  • Rashness/Scaly Skin
    Contact dermatitis often leads to rashes and scaly skin. Many allergens can cause your skin to respond with a rash or scales, such as mold.
  • Headache/ Dizziness
    This is a harder symptom to pinpoint because headaches and dizzy feelings can have many causes. However, this is also an allergy symptom.
  • Chronic Fatigue Tiredness
    If you are chronically tired and always feel fatigued, it may be because of your allergies.

Does a Dehumidifier Help Relieve Allergies?

A dehumidifier can help relieve allergies by preventing some allergy triggers from coming into contact with you. By regulating the relative humidity levels and removing moisture from the air, dehumidifiers can improve air quality in your home and remove some of the leading causes of allergies.

3 Ways Dehumidifiers Relieve Allergies

Stop Mold Growth

Mold grows in moist, humid environments but a dehumidifier can prevent mold growth by lowering your indoor humidity levels. The dryer air will remove existing mold and create a drier environment that will prevent mold growth in the future. The lower humidity level prevents mold spores from entering the air and triggering your allergies.

Eliminate Dust Mites

Dust mites are one of the most common allergens in high humidity areas, but a dehumidifier can stop them from multiplying by lowering the relative humidity. Dust mites are similar to mold spores in that they thrive in a hot, humid environment. Dust mites can’t survive without moisture in the air, so if you use your dehumidifier to keep the relative humidity between 40-50% you can eliminate most dust mites from your home. [3]

Mite Aceria Anthocoptes Acari

Dehumidify Your Crawl Space For An Allergen-Free Home

Crawl spaces are sometimes described as ‘mold amplification’ environments [4] and they can act as a breeding ground for spores, mold growth, mildew, dust mites, and other pollutants which can cause allergic reactions. Dehumidifiers can help to regulate the relative humidity in crawl spaces to stop these pollutants and allergens from entering your home in the first place – providing proactive allergy relief.

If you have a crawl space and live in humid climates, we highly recommend purchasing a dehumidifier specifically for this area and placing it there permanently to ensure that the area isn’t too moist.

How Different Types Of Dehumidifiers Help Relieve Allergies

Refrigerant Dehumidifiers

Refrigerant dehumidifiers are an energy-efficient way to regulate the relative humidity and limit allergens in your home. They work like a fridge and use a fan to bring air into the machine and then cool it quickly over metal plates. As the moisture condenses, water will drip into the tank.

Refrigerant dehumidifiers work well in high-humidity areas because they run for long times to remove moisture from the air. In doing so, they lower air pollution, limit mold growth, and kill dust mites, helping to prevent allergy symptoms. Unfortunately, refrigerant dehumidifiers don’t work as well in cold environments as the coils can freeze.

Desiccant Dehumidifiers

Desiccant dehumidifiers work well in cold environments and are particularly effective at pulling water out of hard materials such as concrete and hardwood. They are an excellent choice for basements and can help regulate the relative humidity in your entire home. This prevents mold growth and kills dust mites, helping to protect you from allergens.

Unfortunately, they are the most expensive option for dehumidifiers and can work more slowly than refrigerant dehumidifiers. However, they work well in smaller areas or rooms.

Whole House Dehumidifiers

A whole-house dehumidifier is large enough to dehumidify your entire home. These work best to remove dust mites and limit mold growth long-term and keep allergens out of your home completely. However, they can be expensive to purchase and install.

Whole-house dehumidifiers come in three types: refrigerant dehumidifiers, desiccant dehumidifiers, and thermo-electric dehumidifiers. All three of these types can work well at removing allergens, depending on your particular situation.

Thermo-electric dehumidifiers are the most affordable and include small desktop models (rather than the whole house size). However, refrigerant and desiccant dehumidifiers are generally more powerful.

Using Dehumidifiers for Allergy Relief In 4 Easy Steps

Using a dehumidifier effectively will lower the relative humidity, remove moisture from the air, and in doing so prevent dust mites and other pollutants from triggering your allergies. Here’s how to do it:

#1 — Purchase the Dehumidifier and Put it Together

Find a dehumidifier which will work in your home. You should consider the size of the space it will be working in, the capacity of the dehumidifier, and the relative humidity it has to deal with. Some dehumidifiers come with built-in air purifiers and this can be valuable if you suffer badly from allergens.

Most dehumidifiers can be assembled within 10-15 minutes and only consist of a few pieces. Refer to your manufacturer’s instructions and assemble.

#2 — Positioning the Dehumidifier

For safety, it is important to pay attention to where you position your dehumidifier in your home. Keep your dehumidifier away from furniture, walls, curtains, and beds so that the air can move freely through the machine.

We recommend placing the machine in the area of your home where the most moisture exists and where the relative humiditiy level is highest. This will allow it to reduce the humidity level and remove water vapor most effectively, stop black mold forming, and kill dust mites. If you can, position a dehumidifier on each floor (basement, downstairs, and living room, upstairs).

#3 — Running the Dehumidifier

Once your dehumidifier has been assembled and positioned in your home, it is time to run the machine. We typically recommend setting your dehumidifier between 35% and 45% humidity as this prevents mold growth and destroys dust mites, but some people are comfortable with slightly higher or lower humidity levels. Make sure that you frequently check the tank so that you can empty the water that accumulates.

If there is too much water in the tank, the dehumidifier will shut off and will not run. Most people need to empty their dehumidifier every 1-2 days, depending on the size of the dehumidifier and how long it has been running.

#4 — Clean & Maintain The Dehumidifier

To get the best results and lower the relative humidity then your dehumidifier needs to be in good condition. It’s important that you clean the air filters, water reservoir, and coils regularly or your device can be the ideal environment for dust mites and can actually encourage mold growth in the relative humidity within the device.

If you maintain your dehumidifier properly then it should help to control the humidity level and protect your from allergens for 5-10 years.

Woman in Blue Sweater Blowing Nose Due to Allergies

Can A Dehumidifier Make Allergies Worse?

A dehumidifier can make allergies worse if you don’t use them correctly because they can dry out the air too much. Very dry air can make conditions like allergies and asthma worse by drying out your nasal passages and airways [5], so if your dehumidifier is extracting too much moisture then it can make your allergies worse.

Humid environments can lead to mold spores and dust mites, but very dry air can cause irritation too. It’s important to find the right balance and create the ideal environment by using your dehumidifier to keep your humidity levels at 30-50%.

People Also Ask (FAQ)

Air purifier vs. dehumidifier – Which is best for allergies?

An air purifier is better for allergy sufferers than a home dehumidifier because the air filters eliminate allergens from the air, and allergens are the primary cause of allergies. However, dehumidifiers are helpful in high-humidity homes where there is a risk of mold and mildew as they can cause allergies too. A combination of both is often a good idea.

What is better for allergies: dehumidifier or humidifier?

A home dehumidifier works best for those who are allergic to mold and mildew because it can help limit and destroy these allergens. A humidifier adds moisture back into the air and can help with scratchy, itchy throats and noses and some other sinus problems.

Is humidity good or bad for allergies?

Too much humidity and too little humidity are both bad for allergies. Your home should have a 30-50% relative humidity level. If the humidity is too low, we recommend adding a humidifier to your home. If it is too high, we recommend adding a dehumidifier to your home.

What humidity level is best for allergies?

The best humidity level for allergies is between 30% and 50%. We recommend sticking between 35%-45% depending on your specific allergy symptoms. If you tend to experience a dry, scratchy nose and mouth, you will want higher levels of humidity (45%). If not, we recommend lower levels of humidity (35%) to limit mold and mildew growth.


Dust mites, micro-organisms, pollutants, and mold spores can all trigger allergies. Dehumidifiers help control humidity in your home, and in doing so they reduce the amount of these allergens that are present in the air in your home. This means you’re less likely to suffer with allergy symptoms.

A dehumidifier can have a big impact in your home, and hopefully you now know how to use a dehumidifier to relieve allergy symptoms.







Last Updated on January 24, 2023

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.